i submitted a tab, which is incorrect... can I correct it myself, or at least inform UG about that?

You can correct it yourself by following these steps.

www.ultimate-guitar.com (home page) > My UG Profile (located at the top right hand corner of the page) > My contributions (along the left side panel) > Update
D E N V E R B R O N C O S vs. S E A T T L E S E A H A W K S